It seems as if the expression parser isn't 100% compatible with .NET 2.0 anymore.
Is there anyone who can confirm this?

I've tried to debug it, but there are issues getting it to compile on MONO against .NET 2.0 - there are breaking changes between the NCalc and the current version of ANTLR (although this may be fixable by running the antlr tool over the grammar again) and
code/style shortcuts (placing 'get' and 'set' properties with no content) aren't accepted by the MONO compiler.